1. Field of the Invention
The present invention relates to a laser annealing method for an amorphous silicon thin film, and more particularly, relates to a laser annealing method, a laser annealing apparatus, and a manufacturing process for a thin film transistor, which can reduce a leak current in the thin film transistor.
2. Description of Related Art
In general, thin film transistors (hereinafter referred to as “TFTs”) have a structure in which a gate electrode, a source electrode, a drain electrode, and a semiconductor layer are laminated. In such a structure, a TFT having a polysilicon thin film as the semiconductor layer excels in electron mobility and finds its application in low power displays. It is conventionally known that in a manufacturing process for a TFT substrate, amorphous silicon deposited into a film on the TFT substrate is crystallized into a polysilicon (polycrystalline silicon) film by laser annealing, for example, see, Japanese Patent Application Laid-open Publication No. 2007-335780.